According to Scotty's videos, I would avoid any Ford with Ecoboost engine and/or 10-speed automatic transmission

The original Explorer (talking 1990s Explorers) was decent, but it had a tendency to flip over easily. Ford was caught off guard and rushed a compact, Ranger-based Explorer into production. This was an extremely short-sighted "idea"; SUVs are a lot more top heavy than an equivalent truck. 

Shortly afterwards, Ford learned of the Explorer's tendency to roll over in crashes, so Ford's engineers recommended under-inflating the OEM tires to help minimize the chance of roll-over crashes.

Firestone was not made aware of this and tires started blowing out because their tires were too under-inflated (leading to the derisive name Ford Exploder). Under-inflated tires get really hot, and tires blow when the heat is too extreme. Firestone does not offer OEM tires on any Ford-produced vehicle anymore. 2000s Explorers and Navigators were a little better, at least from a prone to rolling over perspective, because Ford started producing a separate chassis dedicated specifically for the Explorer/Navigator, namely, It had a wider wheel track. The best ones were from the mid-2000s.

Starting in 2011, Ford started producing unibody Explorers, blurring the line between a station wagon and an SUV. Ford produced the Explorer and Taurus together on the same platform. Ford started integrating the water pump and engine together to save money on their end, and water pump failures often resulted in engine failure too, as you cannot tell the water pump is leaking on an internally mounted water pump. 

Bottom line is, avoid these SUVs. SUVs from the mid-2000s are now 20 years old, and any reliability they may have once had is pretty much zilch now. 

The Exploder is probably the WORST vehicle Ford ever made. Every generation has problems, and the transmission is the top problem. Just don't even think about it.